1. Field of the Invention
The present invention generally relates to computer systems and more particularly to a method and system for performing intelligent background data conversion.
2. Description of the Related Art
Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
With the popularity of portable devices capable of playing video content, the need to convert source video content to accommodate the decoding capabilities, display resolutions, and user experience of these devices has grown significantly. FIG. 1 is a simplified block diagram of a prior art computing device that performs the needed data conversions. Suppose a user of computing device 100 would like to store a certain video signal input 110, which may be a high-definition television broadcasting (“HDTV”) signal, captured by a capture device 115 coupled to a graphics system 106 in a portable device 120 for display. Typically, HDTV broadcasting signals are compressed based on the Moving Picture Experts Group-2 (“MPEG-2”) standard. In contrast, portable devices generally support playing back compressed video data based on the MPEG-4 standard. In a prior art approach, after video signal input 110 is captured by capture device 115 and directed to graphics system 106, graphics system 106 stores the captured MPEG-2 data in mass storage 118. These captured MPEG-2 data are referred to as the source data. Then, at the request of the user, conversion software 114 is loaded into system memory 112 to be executed by a processing unit 102. When conversion software 114 is executed, processing unit 102 retrieves the MPEG-2 data from mass storage 118, transcodes the MPEG-2 data to the MPEG-4 data required by portable device 120, and causes the transcoded MPEG-4 data to be stored in portable device 120. The MPEG-4 data are referred to as the target data.
One shortcoming with this approach is the monopolization of the processing capacity of processing unit 102 when performing data conversion, in this instance, transcoding. In other words, during the execution of conversion software 114, processing unit 102 dedicates much of its processing capacity to the transcoding operations and becomes unresponsive to requests from other processes within computing device 100. In some instances, the amount of time required to transcode the source MPEG-2 data may take a significant portion of the total time between initiating the storing request and completing the storing of the target data in portable device 120. Similar issues also exist for prior art approaches that focus on another type of data conversion, transrating. In particular, converting the bit rate of the source data to the bit rate of the target data also occupies significant processing cycles of processing unit 102 and, therefore, negatively impacts the overall performance of computing device 100.
As the foregoing illustrates, what is needed in the art is a technique that for performing data conversions that addresses at least one of the problems set forth above.